1. Field of the Invention
The present invention relates to a plasma display device.
2. Description of the Related Art
An AC plasma display device (PDP) comprises a plasma display panel having two glass substrates disposed opposite to each other and a circuit part for controlling and driving. One of the two glass substrate has a plurality of address electrodes disposed in parallel with each other, and the other glass substrate has a plurality of sustain electrodes disposed in parallel with each other and perpendicular to the address electrodes. The sustain electrodes include X-electrodes and Y-electrodes which are disposed in an alternate fashion. Display cells are formed between the adjacent X-electrode and Y-electrode. The circuit part includes several driving circuits for supplying driving voltages to the electrodes of the substrate. Flexible printed circuit boards are used to connect the terminals of the electrodes of the glass substrate with the driving circuits.
The electrodes of the glass substrates are formed linearly in such a manner as to extend substantially across the substrates, and terminals of the electrodes are formed at the ends of the glass substrates. The driving circuits are disposed on a chassis mounted on the outer surface of one of the glass substrates, whereby the driving circuits are disposed within an area occupied by the glass substrate having a large area, this helping prevent the further increase in the overall size of the plasma display device.
Therefore, the plane in which the electrodes and terminals of the glass substrate are disposed is different from the plane in which the driving circuits are disposed. Thus, one ends of the flexible printed circuit boards are connected to the terminals of the electrodes of the glass substrate and the other end to the driving circuits directly or via an intermediate circuit board connected to the driving circuit, with the intermediate portions of the flexible printed circuit boards being bent. Thus, the use of the flexible circuit boards is reasonable and effective.
AC plasma display device of this type is disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 11-327503 and No. 11-327458.
Conventionally, terminals formed at one end of the flexible printed circuit board are fixed and connected directly to terminals of electrodes on the glass substrate through thermal-compression bonding using an anisotropic conductive film. The anisotropic conductive film comprises a thermoplastic resin and metallic particles dispersed in the resin and has a function as an adhesive for mechanically bonding the flexible printed circuit board to the glass substrate and a function as a conductive member for electrically connecting terminals of the electrodes of the glass substrate with terminals of one end of the flexible printed board.
In addition, Japanese Unexamined Utility Model Publication (Kokai) No. 63-6674 discloses a construction in which terminals formed at one end of the flexible printed circuit board are connected to terminals of electrodes of the glass substrate, and thereafter, the flexible printed circuit board is pressed and held onto the glass substrate using a clip, and a deviation preventing metal fixture is additionally used. Japanese Unexamined Patent Publication (Kokai) No. 10-83873 discloses a connector for a portable apparatus in which the glass substrate is connected to the circuit board without using flexible printed circuit boards.
Terminals are provided on the glass substrate at a very small pitch and it is especially small on the address side. A certain length of time is required to accurately align the terminals on the flexible printed circuit boards with those provided on the glass substrate in a thermal bonding process. In addition, in this process, the thermoplastic resin needs to be heated to a sufficient temperature for deformation, and time is also needed until the heated thermoplastic resin is set with the heated condition being maintained after thermal bonding, thus a relatively long period of time is needed when compared with other processes.
In addition, a pair of glass substrates are integrated into a plasma display panel, and the flexible printed circuit boards are then fixed to the glass substrates integrated into the plasma display panel. In the event that something abnormal occurs in either the flexible printed boards or the plasma display panel after the flexible printed circuit boards are fixed to the glass substrates, the flexible printed circuit boards cannot be removed from the display panel, this causing a situation in which neither the flexible printed circuit boards nor the plasma display panel can be used any more. Due to this, in the event that the flexible printed circuit boards produce defects that cannot be recovered, whereas the plasma display panel is still in good condition, the expensive plasma display panel cannot be used.
Therefore, a connector has been demanded which can removably fix both members to each other without directly fixing the flexible printed circuit board to the glass substrate. Furthermore, a reduction in working time during the connecting process is required. In addition, it is also required to independently replace a member suffering from a failure in the event there occurs a failure for some reason in a member in the circuit portion including the flexible printed circuit boards and the plasma display panel. Thus, it is desired that the environment should be protected from being adversely affected by reducing the number of members wasted, as well as reducing the price of products. In addition, this problem also applies to similar flexible connecting members such as flat cables and flat flexible cables.
The object of the present invention is solve the aforesaid problem, and to provide a plasma display device in which flexible members can be detachably attached to a substrate by connectors.
According to the present invention, there is provided a plasma display device comprising a pair of substrates, each substrate having a plurality of electrodes and a plurality of terminals provided at ends of respective ones of the plurality of electrodes, a driving circuit for supplying a driving voltage to the electrodes on one of the substrates, a flexible connecting member comprising plural conductors extending from the driving circuit, and a connector detachably attached to the substrate, each connector having a housing and a plurality of terminals disposed in the housing, the terminal having a first portion contacting a terminal of the electrode and a second portion contacting a corresponding conductor of the flexible connecting member.
In the above construction, the terminals of the flexible connecting members such as the flexible printed circuit boards are not connected directly to the electrodes of the substrate but are electrically connected to the substrate via connectors electrically connected with the end of the substrate. Consequently, the flexible connecting members can be separated from the substrate by removing the connectors from the substrate. In addition, work for connecting the flexible connecting members to the substrate with the connectors can be carried out more simply and in shorter time than work for connecting the flexible connecting members to the substrate through thermal-compression bonding using an anisotropic conductive film.